Vacuum cleaner with improved fan arrangement



y 1951 M. D. TUPPER 2,983,432

VACUUM CLEANER WITH IMPROVED FAN ARRANGEMENT Filed Sept. 19, 1956 3 Sheets-Sheet 1 WIHTHJ T WE 7* MNI' I r 38 [fit 6Z2 tor: I Myra/2097061; 24 7 y W his Attorney.

y 1961 M. D. TUPPER 2,983,432

VACUUM CLEANER WITH IMPROVED FAN ARRANGEMENT Filed Sept. 19, 1956 5 Sheets-Sheet 2 z glm Myra/2 0. 320 052";

VACUUM CLEANER WITH IMPROVED FAN ARRANGEMENT Filed Sept. 19, 1956 M. D. TUPPER May 9, 1961 3 Sheets-Sheet 3 PERM/N075 w w mswi km W M m. a m

MS fit zap/ the low-head high-flow United States, Patent VACUUM CLEANER WITH INIPROVED FAN ARRANGEMENT Myron D. Tupper, FortWayne, Ind., assignor to General Electric Company, a corporation of New York Filed Sept. 19, 1956, Ser. No. 610,769 11 Claims. (Cl. 230-40) This invention relates to fluid moving equipment, and more particularly to an improved vacuum cleaner provided with a special fan arrangement.

Vacuum cleaners are used under varying conditions where different responses of the cleaner are necessary to effect the desired purpose. Thus, when a vacuum. cleaner is being used to clean a smooth surface, it is desirable that a high flow of air be provided but it is not necessary that a high vacuum be achieved; in fact, it often is not desirable to provide a high vacuum in cases where the flow is high because of the load placed on the vacuum cleaner motor. On the other hand, where the vacuum is used to clean fabric surfaces such as tapestries, sofas, and the like, it is important that a high suction be provided to draw air through the cloth so as to take up threads and other items attached to the fabric. Thus, where the flow is low because of the obstruction of the fabric against the nozzle of the vacuum cleaner, it is important that the suction provided be high. While todays vacuum cleaners provide a headto-flow relationship wherein the head decreases as the flow increases, only a relatively gradual change in head as the flow increases has in the past been achieved. The optimum situat'on is to have a very high head at low flow, decreasing head as the flow increases beyond a very small amount. The characteristics of the head and amount of flow are, of course, primarily determined by the type of fan driven by the motor of the vacuum cleaner.

It is, accordingly, an object of this invention to provide an improved fan arrangement which will efiect a high head at very low flows and a much lower head at higher flow rates.

Another object of the invention is the incorporation of such a fan system in a vacuum cleaner.

In one aspect thereof, the invent-ion provides, in a vacuum cleaner, a casing forming a passage for air, with a low-head high-flow fan arranged beyond the passage in series flow relation therewith. A valve is positioned beyond the fan in series flow relation therewith, and is arranged to open when a predetermined flow of air (at a low head) through the passage is efiected. A bypass around the valve is provided, and a high-head low-flow type of fan is arranged in the bypass so as to be effective when the valve is closed, thereby providing a high head when the flow of air decreases to a certain value. However, above that level of flow, with the valve open, the major part of the air will be moved by fan with the result that the head will decrease very rapidly at fiow values above the opening point of the valve.

More particularly, it is proposed to incorporate such a fan arrangement in a vacuum cleaner where the casing of the vacuum cleaner and the housing of the electric motor positioned in the casing form at least part of the necessary air passages. 1

With the above described arrangement, when a low flow condition is created bysubstantial obstruction of the rapidly to a relatively constant low 2,983,432 Patented May 9, 1961 vacuum cleaner nozzle, the valve will be closed and the high-head fan will create the necessary high degree of suction. However, when a smooth surface is being cleaned and there is relatively little obstruction of the vacuum cleaner nozzle, the amount of flow will be suflicient to open the valve, the high-head fan will be substantially bypassed, and a high degree of flow will be achieved at a relatively low head because of the characteristics of the fan in series with the valve.

The features of the invention which are believed to be novel are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, together with fur ther objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings.

In the drawings,

Figure 1 is a side view, partly broken away and partly in cross section, of the improved fan arrangement of this invention together with operating means therefor;

Figure 2 is a view in perspective of a canister-type vacuum cleaner incorporating the improved construction of this invention;

Figure 3 is a schematic diagram of the flow circuit of the physical arrangement of Figures l and 2;

Figure 4 is a view along line -4-4 in Figure 1;

Figure 5 is a schematic diagram of an alternative improved flow circuit usable in a vacuum cleaner;

Figure 6 is a fragmentary side view, partly in cross section, illustrating a construction incorporating the flow circuit of Figure 5; and

Figures 7, 8, and 9 are flow curves illustrating the desirable effect of the construction of the invention as set forth in Figures 1 to 4.

Referring now to Figures 1, 2, and 4 of the drawings, there is shown a vacuum cleaner of the canister type, generally indicated at 1, including a casing 2 having an opening 3 provided at the top thereof and formed in the usual manner to receive end 4 of a hose 5 terminating in a cleaning tool 35. A bag 6 of porous material (designed to retain dirt and let air pass through) is provided in the usual manner with an open end thereof (not shown) arranged in engaging relationship with opening 3. In order to create the necessary suction to pull air through hose 5 and bag 6, a suitable fan arrangement generally indicated at 7, which will be more fully described below, is provided.

Fan arrangement 7 is operated through a shaft 8 by a motor, generally indicated at 9, positioned within casing 2 as best seen in Figure 2. While its construction is not a part of the invention, motor 9 is generally of the alternating current series type with an armature 10, a commutator 11 and brushes 12. The functioning of such motors is well known in the art and thus will not be described herein other than to state that when the motor 9 is connected to a suitable source of alternating current power, armature 10 and shaft 8 will rotate. The motor parts are positioned in a motor cavity formed by motor housing 13 which is provided with openings 14 at its upper, or brush end, as shown. In addition, there is provided a sealing arrangement 15 which extends between the motor housing 13 and the vacuum cleaner casing 2 so as to forma seal therewith. This forces the air drawn in through hose 5 and opening 3 to pass through openings 14 in the motor housing 13 and then through the motor itself.

A fan casing member 16 is secured to flange 17 of motor housing 13 by threaded members 18. Shaft 8 is rotatably supported within member 16 by means of bearing 19. Concentrically secured td the end 20 of shaft 8 so as torotate therewith is a fan impeller member, generally indicated at 21, which includes a hub 22, a plurality of spaced radial-type fan blades 23, a radially extending separating member, or plate 24, and a plurality of vortex-type fan blades 25 on the other side of the plate. Plate 24 acts eifectively to separate fan blades 23 and '25 so that they act independently as separate fans as will be further described. Radial fan blades 23 are of the type which move air substantially radially outwardly and are designed so as to provide a relatively low head and relatively high flow. A scroll shaped casing member 26 cooperates with member 16 to enclose the radial fan blades 23 to form a radial fan assembly and to provide a proper scroll-shaped passage with an outlet 27 to atmosphere normally closed by a gate-type valve 23 lightly biased to its closed position. Openings 29 are provided in member 16, as shown so that air from motor 9 may pass into the radial fan blades 23 relatively close to shaft extension 2 with blades -23 then moving the air outwardly in the usual manner of radial fans.

The vortex type fan blades 25 on the other side of plate 24- cooperate with an annular chamber 3% formed by portion 31 of member 16 so as to provide a vortex fan assembly. As is well known, this type of fan, as normally designed, provides a very high head at low flows, and loses this head very rapidly as the amount of flow increases. Plate 24 and member 16 are arranged in close running clearance about the rotating parts to minimize the amount of leakage from the fan. An opening 32 to the fan is provided from the motor Q, and the air leaves the fan, passing through opening 33 to atmosphere after having been moved around in a circular path. The space etween openings 32 and 33 is, of course, blocked off by a battle 3% so as to force the air to move around substantially the entire annular path before being discharged.

Referring now to Figure 3, the air flow in the vacuum cleaner 1 described in Figures 1, 2,. and 4 (and shown by the arrows in those figures) is schematically illustrated. As has been described, the air enters the vacuum cleaner through tool 35, hose 5 and the passage formed by opening 3 casing 2, and passes through the bag 6 and the motor 9. This portion of the air travel is illustrated by the line segment a in Figure 3, with the arrow being provided to show the direction of flow. The air path is then split into [2 and c, which represent respectively the openings 32 and 29 provided from the motor 9 to the vortex fan and the radial fan 23 respectively. Radial fan 23 is in series flow relation with gate valve 23, While the vortex fan 25, which exhausts directly through opening 33, is across the gate valve. This illustrates the fundamental fan relationship constituting the essence of this invention: radial tan 23 (a low-head high-flow fan) is in series relationship with flow-sensitive valve 28, and vortex fan 25 (a high-head low-flow fan) is in parallel relationship with flow-sensitive valve 28. With this arrangement, up to a predetermined amount of flow, valve 28 will remain closed and what how there is will pass through vortex fan 25.

Referring now to Figure 5 of the drawings, there is shown the head-flow curve for a vortex fan *25' Where motor 9 provides a speed of rotation of 16,000 rpm. and the fan has a mean diameter of four inches (a typical vacuum cleaner arrangement). It will readily be observed that at low flow the head (or suction) of the vortex fan is very high, and that this head decreases to a value of substantially zero at approximately seven cubic feet per minute. With valve 23 closed, what air flow there is must come from tool and will be channeled through the vortex pump and the desired high head will be obtained. However, when the amount of air passing through the vacuum cleaner increases, flow sensitive valve '23 opens and the radial fan 23 then operates at a low head to provide the desired high flow, with the vortex ian being substantially bypassed and, in any event, preeluded from creating a high head by the amount of flow. Figure 5 represents the head-flow curve for a radial fan or the type described rotating at 16,000 r.p.m. and having a diameter of 5.3 inches. It will be seen that the amount of suction created by the radial fan is relatively low at all times but that the fan is capable of providing a high flow rate. Reference to Figure 7 shows the combined effect of the two types of fan in the vacuum cleaner 1 in the type of structure described in Figures 1, 2, and 3. At low flow the vortex fan will provide the desired high head, with valve 28 causing all the flow to pass through the vortex fan. As the flow increases, as it will where the vacuum cleaner nozzle is substantially unobstructed (as where a smooth surface is being cleaned), valve 28 opens to permit the radial fan to become efiective independently of the vortex fan. The radial fan will then provide the desired high flow at the desired low head, and the vortex fan will, to a very substantial degree, be bypassed since the flow will take the path of least resistance through the open valve.

It will be seen from the foregoing that the invention provides a special fan arrangement whereby a vacuum cleaner is provided with the desired characteristics for both low-flow conditions and high-flow conditions. In other words at low flow a high head is provided, and at high flow the desired lo'w head is present to prevent overloading of the motor. I

Referring now to Figure 6, there is shown the structure of a modification of the invention. Like numbers to those of Figure 1 will be used to describe like parts, and it will be understood that all parts not illustrated are the same as in the embodiment of Figures 1 to 4. An impeller member 36 has its hub 37 secured to shaft 20 so that the impeller rotates with the shaft. Radial-type fan blades 38 and vortex-type fan blades 39 are secured to plate 49 of impeller 36, with the radial blades 38 being positioned radially inward relative to blades 39. A stationary member 41 includes a scroll shaped portion 42 and a portion 43 which cooperate with plate 40 and blades 38 to form a low-head high-flow radial fan assembly having an inlet 44 and an outlet 45.

Portion 46 of member 41 cooperates with blades 39 and plate 4t) to form a high-head low-flow vortex fan assembly having an inlet 47 and an outlet 38 separated by a baffle 49. A gate-type flow-sensitive valve 5(l, lightly biased to its closed position, normally closes an opening 51 formed in member 41. Both inlet 47 and opening 51 are adjacent outlet 45 of the radial fan assembly.

Referring now to Figure 5, the air flow for the construction of Figure 6 is schematically illustrated. As before, line segment a includes tool 35, hose 5, the passage formed by opening 3 in casing 2, bag 6, and motor 9. Also as before, a low-head high-flow fan and a highhead low-flow fan are provided in series with passage 11, with the former being in series with the valve and the latter being in parallel across the valve. In this case, however, as opposed to the arrangement of Figure 3, the two fans 38 and 39 are in series with each other (with outlet 45 connected to inlet 47) rather than the high-head fan being in parallel with the low-head fan as shown in Figure 3. With the modified arrangement, the operation is substantially the same; when the vacuum cleaner nozzle is obstructed so as to preclude a high flow rate, valve 50 will close and the fan 39 will be etfective to create a high suction. However, when the obstruction is removed, the amount of flow through the vacuum cleaner increases to the point where valve 50 opens, thus effectively bypassing fan 39 and permitting the flow to pass directly through the low-head high-fiow fan 38 and then out of the cleaner. The arrangement of Figures 5 and 6 illustrates the fact that the important features are the characteristics of the fans and the relation of each fan to the valve.

While the invention has been explained by describing particular embodiments thereof, it will be apparent that improvements and modifications may be made without departing from the scope of the invention as defined in the appended claims.

What I claim as new and desire to secure by Letters tioned beyond said fan in series flow relation therewith,

an outlet for said fan, means connecting said valve between said fan and said outlet, said valve being responsive to open at a predetermined flow of air through said passage, a bypass around said valve, and a high-head low-flow fan arranged in said bypass, said high-head lowilow fan having respectively higher head and lower flow characteristics than said low-head high-flow fan, whereby said low-head high-flow fan moves a substantial amount of air when the entrance to said passage is substantially unobstructed and said high-head low-flow fan provides a substantial head when the air flow decreases because of an obstruction in the entrance to said passage. 2. In a vacuum cleaner, a casing forming an air passage, an electric motor positioned within said casing, a low-head high-flow fan positioned within said casing beyond said passage in series flow relation thereto, said motor having a driving connection to said fan, a valve positioned beyond said fan in series flow relation therewith, an outlet for said fan, means connecting said valve between said fan and said outlet, said valve being responsive to open at a predetermined flow of air through said passage, a bypass around said valve within said casing, and a high-head low-flow fan positioned in said bypass, said high-head low-flow fan having respectively higher head and lower flow characteristics than said lowhead high-flow fan, said motor having a driving connection to said high-head low-flow fan whereby said lowhead high-flow fan moves a substantial amountof air when the entrance to said air passage is substantially unobstructed and said high-head low-flow [fan provides a substantial head when the air flow decreases because of an obstruction in the entrance to said air passage.

1 3. In a vacuum cleaner, a casing forming an air passage, a low-head high-flow radial fan arranged in said casing beyond said passage in series flow relation thereto, a valve in said casing positioned beyond said fan in series flow relation therewith, an outlet for said fan, means connecting said valve between said fan and said outlet, said valve being responsive to open at a predetermined flow of air through said passage, a bypass around said valve, and a high-head low-flow vortex fan arranged in said bypass, said vortex fan having respectively higher head and lower flow characteristics than said low-head high-flow fan, whereby said radial fan moves a substantial amount of air when the entrance to said passage is substantially unobstructed and said vortex fan provides a substantial head when the air flow decreases because of an obstruction in the entrance to said passage.

4. In a vacuum cleaner, a casing forming an air passage, an electric motor positioned within said casing, a rotatable shaft extending from said motor, a low-head high-flow fan secured to said shaft concentrically therewith within said casing beyond said passage and in series ilow relation therewith, a valve positioned beyond said fan in series flow relation therewith, an outlet for said fan, means connecting said valve between said fan and said outlet, said valve being responsive to open at a predetermined flow of air through said passage, a bypass around said valve within said casing, and a high-head low-flow fan positioned in said bypass and secured to said shaft concentrically therewith said high-head lowfiow fan having respectively higher head and lower flow characteristics than said low-head high-flow fan, whereby said low-head high-flow fan moves a substantial amount of air when the entrance to said passage is substantially unacsaaaa obstructed and said high-head low-flow fan provides a.

substantial head when the 'air flow decreases because of an obstruction in the entrance to said passage.

5. In a vacuum cleaner, a casing forming an air passage; an electric motor positioned within said casing; a rotatable shaft extending from said motor; a member concentrically secured to said shaft to rotate therewith, said member including a radially extending plate, and two pluralities of fan blades respectively positioned on each side of said plate; stationary means arranged adjacent said concentric member in cooperative relation with said pluralities of fan blades, one of said pluralities of blades forming in cooperation with the means adjacent thereto a low-head high-flow fan assembly beyond said passage and in series flow relation therewith and the other of said pluralities of blades formingin cooperation with the stationary means adjacent thereto a high-head low-flow fan assembly beyond said passage and in series flow relation therewith; and a valve positioned beyond said low-head high-flow fan in series flow relation therewith and in parallel flow relation with said high-head low-flow fan, said valve being arranged to open at a predetermined flow of air through said passage whereby said low-head high-flow fan moves a substantial amount of air when the entrance to said passage is substantially unobstructed and said high-head low-flow fan provides a substantial head when the airflow decreases because of an obstruction in the entrance to said passage.

6. In a vacuum cleaner, a casing forming an air passage; an electric motor positioned within said casing; a rotatable shaft extending from said motor; a member concentrically secured to said shaft to rotate therewith, said member including a radially extending plate and two pluralities of fan blades respectively positioned on opposite'sides of said plate; stationary means arranged adjacent said concentric member in cooperative relation with said pluralities of blades, one of said pluralities of blades forming in cooperation with the means adjacent thereto a low-head high-flow radial fan assembly beyond said passage and in series flow relation therewith, said stationary means adjacent said radial fan forming a scroll-type housing, and the other of said pluralities of blades forming in cooperation with the means adjacent theretoa high-head low-flow vortex fan assembly beyond said passage and in series flow relation therewith, said vortex fan having an outlet independent of said radial fan; and a valve biased to close the outlet of said radial fan scroll-type housing and arranged to open at a predetermined flow of air through said passage whereby said radial fan moves a substantial amount of air when the entrance to said passage is substantially unobstructed and said vortex fan provides a substantial head when the air flow decreases because of an obstruction in the entrance to said passage.

7. In a vacuum cleaner, a casing forming a passage for air, a low-head highfiow fan arranged beyond said passage in series flow relation therewith, a valve positioned beyond said fan in series flow relation therewith, an outlet for said fan, means connecting said valve between said fan and said outlet, said valve being responsive to open at a predetermined flow of air through said passage, a bypass around said valve and said low-head highflow fan, and a high-head low-flow fan arranged in said bypass, said high-head low-flow fan having respectively higher head and lower flow characteristics than said lowhead high-flow fan, whereby said low-head high-flow fan moves a substantial amount of air when the entrance to said passage is substantially unobstructed and said high-head low-flow fan provides a substantial head when the air flow decreases because of an obstruction in the entrance to said passage.

8. In a vacuum cleaner, a casing forming a passage for air, a low-head high-flow fan arranged beyond said aesaa-se passage in series flow relation therewith, a 'valve positioned beyond said fan in series flow relation therewith, an outlet for said fan, means connecting said valve between said fan and said outlet, said valve being responsive to open at a predetermined flow of air through said passage, and a high-head low-flow fan arranged in parallel flow relation with said valve and in series flow relation with said low-head high-flow fan whereby said lowhe'ad high-flow fan moves a substantial amount of air when the entrance to said passage is substantially unobstructed and said high-head low-flow fan provides a substantial head when the air flow decreases because of an obstruction in the entrance to said passage.

9. An electric motor, a rotatable shaft extending from said motor, a low-head high-fiow fan secured to said shaft concentrically therewith, a high-head low-flow fan secured to said shaft concentrically therewith, stationary means secured to said motor adjacent said fans in coperative relation therewith to complete low-head highfiow and high-head low-flow fan assemblies respectively, and a flow sensitive valve secured to said stationary means in series flow relation with said low-head highflow fan and in parallel flow relation with said highhead low-flow fan whereby said low-head high-flow fan moves a substantial amount of air when the inlet to said fans is substantially unobstructed and said highhead low-flow fan provides a substantial head when the air flow decreases because of an obstruction in the inlet to said fans.

10. An electric motor including a housing forming a motor cavity; a rotatable shaft extending from said motor; a member concentrically secured to said shaft to rotate therewith, said member including a radially extending plate, and two pluralities of fan blades respectively positioned on each side of said plate; stationary means secured to said motor housing and arranged adjacent said concentric member in cooperative relation with said pluralities of fan blades, one of said pluralities of blades forming in cooperation with the means adjacent thereto a low-head high-flow fan assembly, the other of said pluralities of blades forming in cooperation with the means adjacent thereto a high-head lowflow fan assembly, each of said fans having an inlet communicating with the motor cavity and having an outlet communicating with atmosphere; and a flow-sensitive valve secured to said stationary means and positioned to close said low-head high-flow fan outlet, said valve being arranged to open at a predetermined flow of air through said motor whereby said low-head high-flow fan moves a substantial amount of air when the inlet to said fans is substantially unobstructed and said high-head low-flow fan provides a substantial head when the air flow decreases because of an obstruction in the inlet to said fans.

11. An electric motor including a housing forming a motor cavity; a rotatable shaft extending from said motor; a member concentrically secured to said shaft to rotate therewith, said member including a radially extending .plate, and two pluralities of fan blades secured to said plate and radially displaced from each other; stationary means secured to said motor housing and arranged adjacent said concentric member in cooperative relation with said pluralities of fan blades, the inner of said pluralities of blades forming in cooperation with the means adjacent thereto a low-head high-flow fan assembly having an inlet and an outlet, the outer of said pluralities of blades forming in cooperation with the means adjacent thereto a high-head low-flow fan assembly having an inlet and an outlet, said low-head fan inlet communicating with the motor cavity, said high-head fan inlet communicating with said low-head fan outlet; said high-head fan outlet communicating with atmosphere,

said stationary means having an opening formed therein between's'aid low-head fan outlet and said high-head fan inlet; and a flow-sensitive valve secured to said stationary means and positioned to close said opening, said valve being arranged to open at a predetermined flow of air through said motor whereby said low-head fan moves a substantial amount of air when the entrance to said motor cavity is substantially unobstructed and said high-head fan provides a substantial head when the air flow decreases because of an obstruction in the entranceto said motor cavity.

References Cited in the file of this patent UNITED STATES PATENTS 1,465,041 Losel Aug. 21, 1923 2,044,830 Carlstedt June 23, 1936 2,391,486 Smith Dec. 25, 1945 2,624,064 Snyder Ian. 6, 1953 2,632,914 White Mar. 31, 1953 2,701,530 Schellerer Feb. 8, 1955 2,788,171 Kulow Apr. 9, 1957 FOREIGN PATENTS 114,967 Switzerland May 17, 1926 158,673 Australia Sept. 8, 1954 536,197 Great Britain May 6, 1941 680,001 Great Britain Oct. 1, 1952 711,791 Germany Oct. 7, 1941 855,407 France May 10, 1940 

